A legal dispute between the state's top tax official and Fulton County that could hit thousands of county property owners in the wallet moved to a new phase as the case went to appeals court.

At issue is whether the county had the authority to freeze residential property values in 2017 at a time when many property owners were complaining about a rapid rise in property values.

The state revenue commissioner, Lynnette Riley, on Friday appealed a judge's December ruling that said she was "without legal authority" when she decided to reject Fulton's 2017 tax digest because of county leaders' decision to resend new property assessments in response to public outrage.

VIDEO: Previous coverage of Fulton taxes

Channel 2's Richard Belcher reports

In the appeal filed in Georgia’s Court of Appeals, Riley’s attorney said DeKalb County Judge Alan C. Harvey erred when he ruled that a local board of commissioners can “disregard and overrule property valuations” made by the independent board of assessors, which she said was “contrary to state law.”

If Riley is successful in her appeal, Fulton homeowners could be re-billed for disputed property taxes.

The county, for years, failed to keep up with rising values. In 2017, Fulton commissioners relied on an 1880s Georgia law to modify the tax digest and send a revised set of assessments after thousands of Fulton homeowners complained about skyrocketing values. Nearly a quarter of the 318,000 residential parcels in the county had assessments that were up 50 percent or more, while half were up by at least 20 percent.

Riley, in the appeal, said the county was not aware of the 19th century law when it made the decision and the law was “effectively repealed” long ago. The county’s action was in direct conflict with state law that only lets boards of assessors and the revenue commissioner correct values, she said.

Riley said Harvey's December ruling that found the revenue department should be required to accept the 2017 tax digest, which it had rejected, was wrong.

Harvey allowed “an elected body to interfere with independent appraisals and state standards mandated by the General Assembly,” Riley’s appeal said.

Jessica Corbitt, a Fulton County spokesperson, said she had no comment on the pending litigation.